Abstract
BACKGROUND AND AIM: Prediabetes is associated with metabolic disturbances that significantly increase the risk of developing cardiovascular disease (CVD). Probiotics and synbiotics may improve metabolic health, but their impact on CVD risk factors in prediabetic adults needs further evaluation. This meta-analysis evaluates the effects of probiotic and synbiotic supplementation on cardiovascular risk factors in individuals with prediabetes. METHODS: An extensive search of scientific databases was conducted from inception through February 2025 to identify relevant randomized controlled trials (RCTs). After screening, data were extracted. A random-effects model was used to compute pooled weighted mean differences (WMD) with 95% confidence intervals (CIs), accounting for study heterogeneity. All statistical analyses were performed using Stata. RESULTS: The pooled analysis of seven RCTs revealed that probiotics and synbiotics supplementation in prediabetic adults had no significant changes in fasting blood glucose (FBG) (WMD: -2.15 mg/dL, p = 0.135), fasting insulin (FI) (WMD: -0.43 µIU/mL, p = 0.526), Homeostasis model assessment of insulin resistance (HOMA-IR) (WMD: -0.31, p = 0.090), triglycerides (TG) (WMD: -5.53 mg/dL, p = 0.614), total cholesterol (TC) (WMD: -1.92 mg/dL, p = 0.730), low-density lipoprotein cholesterol (LDL-C) (WMD: 1.39 mg/dL, p = 0.542), systolic blood pressure (BP) (WMD: -2.24 mmHg, p = 0.480), diastolic BP (WMD: -1.10 mmHg, p = 0.260), body weight (WMD: 0.30 kg, p = 0.861), and body mass index (BMI) (WMD: -0.20 kg/m², p = 0.510). In contrast, a significant improvement was noted in hemoglobin A1c (HbA1c) levels (WMD: -0.16, p < 0.001) and high-density lipoprotein cholesterol (HDL-C) (WMD: 1.63 mg/dL, p = 0.020). CONCLUSION: Probiotics and synbiotics show the potential to improve specific cardiovascular risk factors in prediabetic individuals, notably through reductions in HbA1c and an increase in HDL-C levels. However, their effects on other metabolic markers, such as FBG, insulin resistance, lipid profiles, and weight, remain inconclusive. Further high-quality trials are necessary to fully assess their impact on cardiovascular risks and diabetes progression in this population. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40200-025-01700-x.